irisandClaude Fable 5.1
155d899e55
e1030d6 made Selection's key (RowKey, u32) and changed apply's
ReplaceLast arm to unregister unconditionally rather than only when the
key changed -- correctly, but with nothing exercising it. The case is a
tail row rebuilt under the *same* key with fewer blocks than it had: the
blocks that no longer exist keep pointing at widgets replace_back's drop
frees, and Selection::begin resolves every registered handle on an
ordinary press, so the next tap anywhere in the transcript panics. The
old `if new_key != old_key` guard could not see it, because nothing
about the key changed.
Selection::registered_blocks (test-only) is what lets the test assert the
contract unregister states -- every block of the row, not the first --
instead of only that nothing panicked.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>